1. Field of the Invention
The present invention relates to processor-based computer systems, and more specifically, to a method and a system for automatically sensing processor operating voltage requirements and accordingly adjusting the power supply populated on a printed circuit board to which the processor is coupled.
2. Description of the Related Art
A processor-based computer system is generally known to comprise, at a minimum, an execution unit, memory and various input/output ports. The execution unit is often referred to as a processor, and the processor is typically linked to the memory via a system bus. The system bus, sometimes referred to as a local bus, links address and data information sent between the processor and memory. The system bus can also link the processor, or memory, to various other subsystems, some of which are arranged on a single printed circuit board. The single printed circuit board is often referred to as a motherboard.
Recent developments in processor technologies provide for an increasing number of different processor types available in the market. Generally, these processors can be used for similar and dissimilar fields of applications. With the increase in the number and complexity of available processors, it becomes increasingly difficult to know the voltage requirements of a specific processor. Voltage requirements include, for example, the level of voltage and the number of levels needed to operate the processor.
As finer geometries are becoming achievable through advances in digital integrated circuit manufacturing processes, lower supply voltages are used to insure optimal operation. The lower supply voltage provides advantages for power consumption and reduces cooling requirements of the processors. Furthermore, the lower power supply voltage may be required to prevent damage to internal circuitry of the processor. However, the I/O pins may be required to operate at a higher voltage for electrical compatibility with industry standard interfaces (e.g., socket 7). Therefore, a processor may have dual operating voltage requirements vs. a single voltage requirement for proper operation. For example, Advanced Micro Device's (AMD's) enhanced 0.35-.mu.m manufacturing process requires a lower supply voltage for the core, separate from the voltage used to power the I/O pins (for compatibility reasons).
Further, a substantial percentage of motherboards manufactured today can support multiple configurations. Specifically, modem motherboards come equipped with numerous switches or jumpers, which can alter the operation of one or more subsystems arranged thereon. The voltage supplied to a processor can also be changed, for example, by connecting a jumper or actuating a switch. It is therefore necessary when inserting a processor into a motherboard that the operator know which jumper to connect or which switch to activate.
The availability of a wide selection of voltage supplies in motherboards specifically designed to accommodate many types of processors which may differ in voltage supply requirements presents a need for identifying the correct voltage supply requirements. This flexibility further presents a need to correctly adjust the voltage to be supplied to a processor coupled thereto upon appropriate selection of the processor's operating voltage requirements. For example, typical motherboards may have numerous switches and jumpers, wherein the particular switch and jumper of interest must be identified in order to be properly configured, e.g., the system bus frequency or the processor supply voltage.
Generally speaking, a motherboard is manufactured so that it can accommodate dissimilar processors, including processors that respond to differing power supply voltages. Coupled with today's dissimilar processor needs, it is easy to be confused while connecting a processor to a motherboard. Because of this confusion, many processors are often damaged due to electrical over stress when subjected to incorrect voltage settings during power-up.
One solution to the above problems is a system for detecting jumper and switch settings prior to coupling a processor to the motherboard. Such a system employs a probe and a display remotely linked to the probe. The probe contains a sensor, which responds to signals within the motherboard during times when the probe connects to printed conductors embodying those signals. The sensor is designed to detect the system bus frequency and power supply voltage "seen" by a processor to be connected thereto. Accordingly, the probe may couple to a localized area (or socket) of the motherboard on which a processor is designed for coupling. By knowing the voltage arising from the motherboard, a determination can be made if that voltage is compatible with the to-be-used processor. If the voltage is dissimilar from the processor specification, then the motherboard voltage can be changed by identifying the switch of interest and actuating that switch. However, employing such a system requires that the user is familiar with the processor voltage requirements. Further, the user must also be familiar with the motherboard jumpers and switches applicable to voltage supply. Additional disadvantages of such a system include the need to use an additional and external sensing system in order to identify the current settings of the voltage supply on a motherboard in order to be able to adjust the settings to the one appropriate for the processor to be coupled thereto.
A system for detecting the processor supply voltage requirements operable on the processor itself without the need for an external sensing system is therefore desired. Further, a system including a mechanism that is capable of automatically adjusting the power supply into a processor upon identification of the processor needs is also desirable.